Mobile communication devices, such as cell phones, may utilize the Internet for telephone calls, or other multimedia services, using an architectural framework known as the Internet Protocol (IP) Multimedia Subsystem (IMS). IMS may be utilized in connection with a wireless network based on a Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) standard. A mobile communication device may connect to the IMS using an access network and may send a Session Initiation Protocol (SIP) message to the IMS during call setup. The SIP message may include location information associated with the mobile communication device. The location information may be used by the IMS to determine charging information. However, the location information, included in a SIP message from the mobile communication device, may be viewed as unreliable because it is not provided by the network.